Flattening the Planing Beam – Euclidian Postulates to the Rescue!


It’s been two years since I installed the 8-foot long southern yellow pine 8″x10″ planing beam in the shop, and it has turned out to be my favorite work station.


Occasionally an itinerant minstrel stops by to admire it, and if they are reasonably pleasant I even let them give it a test drive.


For the most part it has stayed stable, but this week I noticed a bit of a crown on the top — of course, worst at the business end of the beam! — so I decided to address it forthrightly.  The timber itself is eight years old — I bought a stack of green SYP timbers like it when I bought the barn thinking I might need them for repairs, but didn’t — so I expect it will still move a bit for another ten or twelve years.


Flattening the beam is truly a straightforward exercise that made me think of my high school math teacher Mr. Fisk, who was pleasantly rigorous in drilling us with Geometry Postulates and Theorems, and many a time one has popped into my head just when I needed it.


Well, one of the most important of the Postulates for woodworkers is the notion that any two intersecting lines establish a plane.  What this means in practice is that if you address any surface with a hand plane, first at 45-degrees to the left, then 45-degrees to the right, when the two patterns meet and cover the entire face you have established a planar surface.


So I did that with a scrub plane, then finished off the surface with a toothing plane to give it a little texture while keeping it flat.  At some point I will deal with the front surface, which is now almost certainly not perfectly square to the top.  But not this week.


Up next will be getting some help in bringing the 14-foot southern yellow pine 10″x 10″ up from the basement to make a really spectacular planing beam. Maybe next month.